Interpolymers of acrylonitrile and a process of producing same



United States Patent INTERPOLYMERS OF ACRYLONITRILE AND A PROCESS OFPRGDUCING SAME Heinrich Hopif, Ludwigshafen (Rhine), and Konrad Jost,Luetzelsachsen, Bergstrasse, Germany, assignors to Badische Anilin- &Soda-Fabrik Aktiengesellschaft, Ludwigshafen (Rhine), GermanyApplication February 3, 1951 Serial No. 209,328

Claims priority, application Germany February 11, 1950 17 Claims. (Cl.260-41) This invention relates to interpolymers of acrylonitrile and aprocess of producing same.

Polyacrylonitrile is eminently suited for making synthetic fibres, inparticular staple fibres and rayon. The threads, contrasted with otherthreads from synthetic organic materials and also with threads fromnatural materials, such as cotton, Wool or silk, can only be dyedunsatisfactorily with the known dyestufis. The same holds good for foilsand other shaped articles from polyacrylonitrile. Moreover, threads,bands and films from polyacrylonitrile tend, when in the stretchedstate, to split ofi lengthwise.

Our present invention relates to interpolymers having an acrylonitrilebase which are free from the said defects. They may be dyed readily andin an inobjectionable manner, and, moreover, do not tend to splitting.

We have found that such polymers are obtained by polymerizing mixturesof preponderating amounts of acrylonitrile and minor amounts of a vinylimidazole, such as l-vinyl imidazole itself, vinyl methyl imidazole,vinyl ethyl imidazole, vinyl butyl imidazole and vinyl phenyl imidazole.The content of a vinyl imidazole in the interpolymers may preferablyamount up to about 20%, more preferably up to 12%, the residue beingacrylonitrile. The lower the percentage of a vinyl imidazole in theinterpolymers, the higher is their melting point, but the less increasedis their capability for being dyed satisfactorily. The best results areobtained with interpolymers of from 98 to 88 percent of acrylonitrileand from 2 to 12 percent of a vinyl imidazole.

The polymerization may otherwise be carried out in a standard fashion.The polymers obtained may be processed, for example spun, fromsolutions, for example in formylpyrrolidone, pyrrolidone propionitrileor dimethyl formamide, by dry or wet spinning methods, and fibres, filmsand other shaped articels are thus obtained which may be dyed withsurprising easiness. Suitable for dyeing are, for example, acid wooldyestuffs, azo dyestufis and their complex chromium compounds as well astriphenylmethane dyestuffs.

The following examples will further illustrate this invention but theinvention is not restricted to these examples. The parts are by weight.

No Drawing.

Example 1 Into a solution of 0.7 part of potassium persulfate in 200parts of water which has been heated to 60 C. there is continuouslyintroduced during the course of two hours, while stirring, a mixture of32 parts of acrylonitrile, 3 parts of vinyl imidazole or of vinyl methylor ethyl imidazole and 0.3 part of triethanolamine.

The polymerization starts immediately and is complete shaft heated to C.and then dried, can be dyed by the processes usual in textile dyeingwith the following dyestuffs: Victoria Fast Violet 2 R extra (Schultz7th edition, vol. 1, page 103), Patent Blue AE (Schultz 7 I/ 109), A20Grenadin S (Schultz 7 I/ 105), Acid Anthracene Brown R (Schultz 7 I/Chrome Fast Orange R (Schultz 7 I/567), Alizarine Direct Blue A 3 G(Schultz 7 Ill/9), Palatine Fast Yellow G R N (Schultz 7 II/ 169),Palatine Fast Red R N (Schultz 7 II/ 169), Palatine Fast Blue G G N(Schultz 7 II/ 168) and others.

Example 2 Into an aqueous solution as specified in Example 1 there isintroduced at the same temperature 'a mixture of 29 parts ofacrylonitrile, 1 part of vinyl ethyl imidazole and 0.3 part oftriethanolamine. tion and processing are as described in Example 1. Thepolymer obtained can be dry-spun or Wet-spun. The threads exhibit goodstrength data and can be dyed with the dyestufis listed in Example 1.

What we claim is: v

1. A process for the production of interpolymers whic comprises heatingan aqueous mixture of a preponderating amount of acrylonitrile and aminor amount of a 1- vinyl imidazole selected from the group consistingof 1- vinyl imidazole, l-vinyl alkyl imidazole, and l-vinylimidazole, inthe presence of a polymerization catalyst, and recovering the resultantpolymer.

2. A process as claimed in claim 1, in which the amounts ofacrylonitrile range between 80 and 98 percent and of a l-vinyl imidazolebetween 20 and 2 percent.

3. A process as claimed in claim 1, in which the amounts ofacrylonitrile range between 88 and 98 percent and of a l-vinyl imidazolebetween 12 and 2 percent.

4. A process as claimed in claim 1, in which l-vinyl imidazole isemployed.

5. interpolymers containing a minor amount of units of l-vinylimidazole, the remainder of the interpolymer consisting of acrylonitrileunits.

6. Interpolymers containing a preponderating amount of acrylonitrileunits and a minor amount of vinyl imidazole units selected from thegroup consisting of l-vinyl imidazole, lvinyl alkyl imidazole, andl-vinyl phenyl imidazole.

7. Intel-polymers containing 98-80% of acrylonitrile units and 2 20% ofvinyl imidazole units selected from the group consisting of l-vinylimidazole, l-v-inyl alkyl imidazole, and l-vinyl phenyl imidazole.

8. Interpolymers containing 98-88% of acrylonitrile units and 2-12% ofvinyl imidazole units selected from the group consisting of l-vinylimidazole, l-vinyl alkyl imidazole, and l-vinyl phenyl imidazole.

9. interpolymers containing a minor amount of l-vinyl alkyl imidazoleunits and the balance of acrylonitrile units.

10. Interpolymers containing a minor amount of 1- vinyl phenyl imidazoleunits and the balance of acrylonitrile units.

11. A shaped article comprising a copolymer of a preponderating weightproportion of acrylonitrile and a minor weight proportion of a substanceselected from the group consisting of l-vinyl imidazole,alkyl-substituted l-vinyl imidazoles, and phenyl-substituted l-vinylimidazoles, said article being dyed with an acid dye.

12. Fibers comprising a copolymer of from 80 to 98 percent by weight ofacrylonitrile and from 2 to 20 percent by weight of a substance selectedfrom the group consisting of l-vinyl imidazole, alkyl-substitutedl-vinyl imidazoles, and phenyl-substituted l-vinyl imidazoles.

Patented Apr. 22, vs

The polymeriza- 13. A fiber a'ccdrdin'g to claim 12 dyed with an acid17. A copolymer of from 80 to 98 percent by weight dye. of acrylonitrileand from 2 to 20 percent by weight of 14. Fibers comprising a copolymerof at least 88 perl-vinyl ethyl imidazole. cent by weight ofacrylonitrile and at least 2 percent by w ight f 1- i 1 i i l 5References Cited in the file of this patent 15. A c'o'polym'er' Of from30 O 98 percent by weight UNITED STATES PATENTS of acrylonitrile andfrom 2 to 28 percent by weight of 1 in 1 i id 1 2,491,471 Arnold Dec.20, 1949 16. A copolymer of from 80 to 98 percent by weight Craig 6t y15, 1952 of ac'rylo'nitrile and from 2 to 20 percent by Weight of 102,643,990 Ham Tune 30, I953 I-vinyl methyl imidazole. 2,688,008 Chaneyet a1 Aug. 31, 1954 V V U S DEPARTMENT OF COMMERCE PATENT OFFICECERTIFICATE OF CORRECTION Heinrich Hopif et alo that error appears in tht requiring correction an Patent Nos 2,831,827 April 22, 1958 It ishereby certified of the above numbered paten Patent should read ascorrected below.

e printed specification d that the said Letters Column 1, line 51, for"articels" read an articles P; column .2,

e" read l vinyl phenyl imidazole a lines 27 and 28, for"l=-vinylimidazol Signed and sealed this 8th day of July 1958,

(SEAL) Attest:

KARL Ho AXLINE ROBERT C. WATSON Commissioner of Patents AttestingOfficer

6. INTERPOLYMERS CONTAINING A PREPONDERATING AMOUNT OF ACRYLONITRILEUNITS AND A MINOR AMOUNT OF VINYL IMIDAZOLE UNITS SELECTED FROM THEGROUP CONSISTING OF 1-VINYL IMIDAZOLE, 1-VINYL ALKYL IMIDAZOLE, AND1-VINYL PHENYL IMIDAZOLE.